VSE, python API: get time point in video file under marker
This will print the Marker time (in seconds since it's corresponding video strip started) with it's corresponding video strip's path for every marker in the scene's timeline.

import bpy

scene = bpy.context.scene

fps = scene.render.fps / scene.render.fps_base

all_markers = sorted(scene.timeline_markers, key=lambda m: m.frame)

all_strips = list(sorted(scene.sequence_editor.sequences,
            key=lambda x: x.frame_final_start))

for strip in all_strips:
    if strip.type == 'MOVIE':
        start = strip.frame_final_start
        end = strip.frame_final_end

        for marker in all_markers:    
            if marker.frame &gt;= start and marker.frame &lt;= end:
                time = (marker.frame - start) / fps
                path = strip.filepath
                print(time, path)